C&D Canal Bridge

Completed in the fall of 1995, this bridge provided a replacement of the S.R. 1 structure over the Chesapeake & Delaware Canal, 30 miles southwest of Wilmington, Delaware.

The new bridge consists of an approach viaduct of 26 spans at 150 ft., leading to a cable-stayed main span of 750 ft. Overall project length is 4,650 ft. with a deck area of 545,560 sq. ft. The structure width is 127-ft. 4-in. and carries three lanes of traffic and two 10 ft. shoulders in each direction. Each approach span consists of 16 precast segments, typically 10-ft. long, 58-ft. 8-in. wide, 12-ft. deep and weighing 70 tons. A total of 640 approach segments were required. These spans have external post-tensioning and are supported by vertically prestressed, precast segmental box piers, resting on 24-in. sq. prestressed concrete piling.

The superstructure was erected using the span-by-span method with an over-head gantry. (Finley McNary developed this scheme, which was proposed by Recchi, prior to the bid.)

The cable-stayed main span unit, utilizes delta frames to anchor the 80 by 0.6-in. strand cable-stays and connect the two roadway segments. The 344 main span segments are similar to those used for the approaches. The cables are continuous through the 325-ft. tall pylon and form a single plane of stays. Erection of the superstructure segments was in one directional cantilever, utilizing 250 ton cranes. To facilitate construction of the pylon, the Contractor proposed to cast it in place using jump forming construction. The Contractor’s bid was $59M.